Lowdown: In addition to avenging a loss to the Sounders in the MLS Cup final in 2016, the Reds won the league's Supporters Shield as well as the Canadian Championship. They set the all-time MLS regular-season record for points with 69. Altidore scored in the 2-0 victory over Seattle and earned MLS Cup MVP honors. Giovinco led the team with 16 league goals. Toronto doesn't appear to be slowing down this season.

Lowdown: Atlanta had a fantastic inaugural season, becoming just the third expansion team to reach the playoffs. United set the MLS attendance record for a season (819,404 tickets sold) and set the single-game record with 71,874 fans on hand to watch the regular-season finale against the Reds. Martinez led the team with 19 goals last season, but eyes will also be on 18-year-old Barco, who was acquired for an MLS-record transfer fee. Barco will miss the first weeks of the season with injury.

Lowdown: The Fire finished third in the East and returned to the postseason for the first time since 2012, but fell in the knockout round to the Red Bulls. In his first MLS season, Nikolic won the league's Golden Boot with 24 goals. One key offseason loss was David Accam, who was traded to Philadelphia. Accam had 14 goals and eight assists last season. The Fire have a good foundation , they just need to stay healthy.

COLUMBUS CREW:

Coach: Gregg Berhalter.

2017 Record: 16-12-6, lost to Toronto FC in the conference final.

Key Players: F Gyasi Zardes, MF Federico Higuain, MF Wil Trapp

Lowdown: One of the league's 10 founding clubs, the Crew's future is currently up in the air. Owner Anthony Precourt announced last season that the team will move to Austin, Texas, following the 2018 season unless a privately financed stadium is built in downtown Columbus. There has been pushback to the move, with supporters using the hashtag #SavetheCrew. The team added Zardes, but scorers from last season, Ola Kamara and Justin Meram, have moved on.

DC UNITED:

Coach: Ben Olsen

2017 Record: 9-20-5, did not make the playoffs.

Key Players: D Steve Birnbaum, F Luciano Acosta, MF Paul Arriola.

Lowdown: Last season was the end of an era for United, which played its final game at RFK Stadium, the team's home for 22 years. This season, United moves to Audi Field, a new soccer-specific stadium. But they won't host a match until July 14, so the team will play the bulk of its games on the road with matches at the Maryland Soccerplex and the Navy Marine Corps Memorial Stadium in Annapolis. United struggled last season, failing to make the playoffs for the first time since 2013.

MONTREAL IMPACT:

Coach: Remi Garde

2017 Record: 11-17-6, did not make the playoffs.

Key Players: MF Ignacio Piatti, MF Saphir Taider, D Michael Petrasso.

Lowdown: This is a dramatically different team from last season. The Impact dismissed coach Mauro Biello at the end of last season and four players retired, including fan favorite Patrice Bernier and Andres Romero. Laurent Ciman was traded to LAFC. But the team added a difference-maker in central midfielder Saphir Taider, who played for three seasons with Bologna. Taider will wear Bernier's No. 8.

PHILADELPHIA UNION:

Coach: Jim Curtin

2017 Record: 11-14-9, did not make the playoffs

Key Players: F/MF David Accam, MF Alejandro Bedoya, F C.J. Sapong.

Lowdown: Brian Carroll retired in the postseason, while Maurice Edu and Chris Pontius have moved on. But adding Accam gave Union fans hope as the team enters its 10th season in the league. The Ghanaian forward should add a little more offense to a team that was primarily known for defense. Sapong led the team with 16 goals and five assists last season, while Haris Medunjanin had 12 assists.

ORLANDO CITY SC

Coach: Jason Kreis.

2017 Record: 10-15-9, did not make the playoffs.

Key Players: MF Sacha Kljestan, F Dom Dwyer, MF Josue Colman.

Lowdown: The Lions have had a busy offseason. Kaka retired and Cyle Larin is playing in Turkey. But the team added proven talent in Sacha Kljestan and Justin Meram. Kljestan, acquired in a trade with the Red Bulls, has led the league in assists for the past two seasons. Meram had 13 goals with the Crew last season. The team also signed 19-year-old midfielder Josue Colman of Paraguay. Up top will be forward Dom Dwyer, acquired last season in a trade with Kansas City.

Lowdown: The biggest departure was captain Sacha Kljestan, who was traded to Orlando City. But the team signed attacking midfielder Alejandro Romero Gamarra, a promising young Argentinian known as Kaku. Veterans Luis Robles and Bradley Wright-Phillips return, surrounded by a bunch of young players that will add depth . Wright-Phillips led the team with 17 goals last season, while Daniel Royer had 12.

NYCFC

Coach: Patrick Vieira.

2017 Record: 16-9-9, lost to Columbus in the conference semifinals.

Key Players: F David Villa, MF Rodney Wallace, MF Jesus Medina.

Lowdown: Losses in the offseason included Italian legend Andrea Pirlo, who retired, and Jack Harrison, who went to Manchester City and is currently on loan to Middlesbrough. The team added Paraguayan winger Jesus Medina, who should start. And there's Villa, of course, who was second in the league with 22 goals last season. He also had nine assists.

NEW ENGLAND REVOLUTION

Coach: Brad Friedel

2017 Record: 13-15-6, did not make the playoffs.

Key Players: MF Lee Nguyen, MF Kelyn Rowe , F Krisztian Nemeth.

Lowdown: The Revolution dismissed coach Jay Heaps last year and brought aboard Friedel, the former U.S. national team goalkeeper. The team has already faced adversity, with midfielder Nguyen requesting a trade at the end of last season and then sitting out the start of camp. Nguyen had 11 goals and 15 assists last season, his fifth with the team. The team lost Kei Kamara, who was traded to the Whitecaps, but signed striker Cristian Penilla from Ecuador.